George Robertson, the formerly UK defence secretary and Nato chief, has claimed Scottish independence would have a "cataclysmic" effect on European and global stability by undermining the UK on the world stage.
The Labour peer told an audience in America that a yes vote would give succour to separatist movements across Europe, risk destabilising Northern Ireland and embolden dictators and "annexers" around the world.
In the most aggressive and pessimistic speech yet by a senior figure in the no campaign, Lord Robertson said many Scottish voters were unaware their decision in September's referendum had implications far beyond Britain.
A breakup of the UK would weaken its global status and a yes vote would leave the UK government embroiled in a complex internal dispute about the terms of Scottish independence just as "solidity and cool nerves" were needed on the world stage. The "loudest cheers" after a yes vote would come from the west's enemies and other "forces of darkness".
"What could possibly justify giving the dictators, the persecutors, the oppressors, the annexers, the aggressors and the adventurers across the planet the biggest pre-Christmas present of their lives by tearing the United Kingdom apart?" Robertson said at the Brookings Institution on Monday.
Can it really be true that the leaders of Russia, North Korea, Belarus and Syria give tuppence for a referendum decision either way on a Scottish independence? Or is George just worried that we might get rid of his beloved nukes?
Some of us are actually worried about the prospects of independence. But this kind of nonsense adds nothing to the debate.